Create a pandas DataFrame from a Cartesian product of two large lists

Question

I'm looking for the simplest way to create a data frame from two others such that it contains all combinations of their elements. For instance we have these two dataframes:

list1 = ["A", "B", "C", "D", "E"]
list2 = ["x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8"]

df1 = pd.DataFrame(list1)
df2 = pd.DataFrame(list2)

The result must be:

   0   1
0  A  x1
1  A  x2
2  A  x3
3  A  x4
4  A  x5
5  A  x6
6  A  x7
7  A  x8
8  B  x1
9  B  x2

I tried to combine from the lists and it works fine with small lists but not for the large ones. Thank you

Answer 1

You can use itertools.product:

import itertools
import pandas as pd

list1 = ["A", "B", "C", "D", "E"]
list2 = ["x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8"]
result = pd.DataFrame(list(itertools.product(list1, list2)))